Using the Synergy between HPLC-MS and MALDI-MS Imaging to Explore the Lipidomics of Clear Cell Renal Cell Carcinoma

Lipid imaging mass spectrometry (LIMS) has been tested in several pathological contexts, demonstrating its ability to segregate and isolate lipid signatures in complex tissues, thanks to the technique’s spatial resolution. However, it cannot yet compete with the superior identification power of high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS), and therefore, very often, the latter is used to refine the assignment of the species detected by LIMS. Also, it is not clear if the differences in sensitivity and spatial resolution between the two techniques lead to a similar panel of biomarkers for a given disease. Here, we explore the capabilities of LIMS and HPLC-MS to produce a panel of lipid biomarkers to screen nephrectomy samples from 40 clear cell renal cell carcinoma patients. The same set of samples was explored by both techniques, and despite the important differences between them in terms of the number of detected and identified species (148 by LIMS and 344 by HPLC-MS in negative-ion mode) and the presence/absence of image capabilities, similar conclusions were reached: using the lipid fingerprint, it is possible to set up classifiers that correctly identify the samples as either healthy or tumor samples. The spatial resolution of LIMS enables extraction of additional information, such as the existence of necrotic areas or the existence of different tumor cell populations, but such information does not seem determinant for the correct classification of the samples, or it may be somehow compensated by the higher analytical power of HPLC-MS. Similar conclusions were reached with two very different techniques, validating their use for the discovery of lipid biomarkers.The work was funded by the Basque Government (IT971-16, IT1162-19, and ELKARTEK KK2018-00090) and has been developed as a Ph.D. project of LMS, who is the recipient of a Predoctoral Fellowship from the Spanish Government (BES- 2016-078721) . The authors are grateful to SGiker Lipidomic Service (UPV/EHU, MICINN, GV/EG, ESF) for the expert advice and technical and human support in MALDI and HPLC- MS analysis

Stacked wire-mesh monoliths for VOCs combustion: Effect of the mesh-opening in the catalytic performance

Structured reactors based on low cost metallic wire-mesh substrates of highly enhanced transport properties can be an interesting alternative to parallel channel monolithic reactors. In this work stacked wire-mesh monoliths were studied for volatile organic compounds elimination. Monoliths of different mesh-opening were homogeneously and adherently dip-coated with Pt/Manganese Octahedral Molecular Sieve (OMS-2) bifunctional catalyst. The catalytic activity was tested in toluene and methanol complete oxidation reactions. Catalytic activity increases using stacked wire-mesh monoliths instead of parallel channel monoliths and decreases when increasing the wire-mesh opening, showing the importance of the mass-transfer phenomena (contact between the gas phase and the solid catalyst).Fil: Sanz, Oihane. Universidad del País Vasco; EspañaFil: Banus, Ezequiel David. Universidad del País Vasco; España. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Investigaciones en Catálisis y Petroquímica ; ArgentinaFil: Goya, Aintzane. Universidad del País Vasco; EspañaFil: Larumbe, Haizea. Universidad del País Vasco; EspañaFil: Delgado, Juan José. Universidad de Cádiz; EspañaFil: Monzón, Antonio. Universidad de Cádiz; EspañaFil: Montes, Mario. Universidad del País Vasco; Españ